Medicinal plants are significant source of synthetic and herbal drugs. Medicinal plants have been used for the treatment of diseases since antiquity. India and China have been on the forefront when we talk about history of herbal drugs. The traditional systems of medicines viz. Ayurveda, Siddha, Unani, Western Herbal Medicine, Traditional Chinese Medicine and Homeopathy have roots in medicinal herbs. Herbal medicine has produced number of distinguished researchers and due to its accessibility to traditions it is still practiced even by lay practitioners.

Ayurveda, the ancient healing system of India, flourished in the Vedic era in India. According to historical facts, the classical texts of Ayurveda, Charaka Samhita and Sushruta Samhita were written around 1000B.C.The Ayurvedic Materia Medica includes 600 medicinal plants along with therapeutics. Herbs like turmeric, fenugreek, ginger, garlic and holy basil are integral part of Ayurvedic formulations. The formulations incorporate single herb or more than two herbs (polyherbal formulations).

The history of Traditional Chinese Medicine is glorious and they have preserved the herbal system beautifully. It originated about 3000 years ago and is a popular science in western countries. Some of the medicinal herbs mentioned in Chinese medicine are common with Ayurveda. Traditional Chinese medicine favors the use of medicinal herbs in natural form rather than extraction. The herbal drugs have different history in Europe and America and they have produced healers like Culpeper. The use of tinctures in Homeopathy is based on medicinal herbs.

Before the availability of synthetic drugs, man was completely dependent on medicinal herbs for prevention and treatment of diseases. The use of the medicinal herbs for curing disease has been documented in the history of all civilizations. The drugs were used in crude forms like expressed juice, powder, decoction or infusion. Although the formulations mentioned in ancient texts are difficult to understand in terms of scientific parameters, but some of them are reputed for their curative values.

Ancient healers, developed formulations based on medicinal herbs, were probably not aware about the chemical composition of the herbs. But the advancement they made despite the non-availability of scientific procedures is astonishing. The work on Terminalia chebula (myrobalan) mentioned in Charaka Samhita is quiet authentical and modern studies have revealed that the purgative activity mentioned in Ayurveda is justified by the isolation of chebulic acid, the active constituent of myrobalan. Initially, the term Materia Medica was coined for the study of natural products. It is further classified into 4 branches.